Feed mechanism for punch presses



Dec. 1,- 1931. i c. G. LILJEBERG FEED MECHANISM FOR PUNCH PRESSES E (40/. Lmaame Filed Nov. 14, 192'? MW mi...

I Mi K iN m 25:: I L RQ 3 Wm I Dec. 1, 1931/ c. e. LILJEBERG 1,834,216

FEED MECHANISM FOR PUNCH PRESSES Filed Nov. 14. 1927 3 Sheets-Sheet 2 CARL G: L/L uEBERG- .By

C. G. LLJEBERG FEED MECHANISM FDR PUNCH PRESSES Dec. 1, 1931.

Filed Nov. 14, 1927 1 753F575 [/VI/E/VTOR 674R $L/Lu BERG? 3 Sheets-Sheet 3 A Try:

25 there is an Patented I El, 1931 warren STATES PAT- ur caries GARE G. mmmme, OF CHICAGO,

ILLINOIS ASIGNOR TO'SEAKEPBOOF LOCK wasnnn conrrmrr, or cmcneo, ILLINOIS, A conronarron or DELAWARE FEED MncE-Amsm roe rune 'rnnssns Application filed November 14, 1927; Serial No. 233,008.

J This invention relates in general to afeeding mechanism for punch presses and has more particular reference to an improved device whereby a metal work strip may be fed positively and punch press for high speed production.

In punch press operation wherein a work strip of metal stock is moved across the dies w ich operate to strike out metal punchings to or form indentations at closely spaced intervals along thework strip, it is desirable to provide a feeding means whereby the strip may be progressively advanced, by exactly similar amounts past the dies while the latter is are inoperative, that is to say, in raised position, in order that the punchings or indentations may be made in the work strip as closely together. as possible without overapp in connection with'punch presses havebeeu of the non-positive type comprisin co-oper atin rollers engaging opposite sides of the wor strip and rotated to drawthe strip through t e punch press. In such devices,

indeterminate amount of tween the work strip and the rollers which causes overlappin and the consequent production of impe ect indentations, the dies striking the strip over anarea including a 80 portion of the indentation formed in the strip by the preceding punching operation. In such devices it is therefore 11 to adjust the mechanisms so that the indenta tions are made at widely spaced intervals in the work strip in order to reduce the number of imperfect punchings produced by the slippage of the work strip at the feeding device. This is a wasteful procedure for where a great number of punchings are made, the jmfinitesimal increase in the spacing between adjacent total amount of scrap material. formed from a given length ofwork stri that is to say, fewer punchings are obtained r unit length of the work strip and the efli duction'is decreased. I Positive feeding of thework strip is also desirable-when. the feeding device. is used ili a punch pressjhaving' progressive dies, that )0 is to say, a punch press in which the indentarapidly between the dies of a the production of In the past, feeding devices used .hf

Another-im is the provislon of a feeding slip be-.

vision of unchin s atl increases the p g gm y of the invention will be apparent as 1t 1s tions are. made progressively, the stock strip being moved successively between difi'erent dies. In such a machine it is obvious that precision feeding is an absolute necessity in erfect work. he principal o ject of my invention is the provision of a positive feed mechanism or punch presses which will feed the work strip rapidly and accurately through the dies of the punch press and promote hi h speed production by eliminating the care formerly needed in ad usting the nonositive feeding devices to operate-in a satis actory manner. other important object of the invention is the provision of an. adjustable feeding mechanism for a punch prew which will space the work accurately and thereby protect the dies from injury and thus prolongin their e by preventing the operation of t e dies on a punched out portion of the work strip. 76

ortant object of the invention mechanism, which .may be adjusted to eed different lengths of a work strip to a.punch press.

Another object of the invention is the provision of a snubbing device, used in connection'with-the automatic feeding mechanism ofa punch press, and a take-u reel for winding up the work strip after it as passed through the feeding mechanism, for preventin the tension," imparted to the stri by the e-up reel, from interfering with t e operation of the feedin device.

Another object o the invention is the ro-v a means for automatically oi ing the work strip as it, passes to the dies of the punch press; and still another object isthe provision'of means for rewindin the strip ti ghtl upon a take-up reel after t e indenta tions ave been made therein.

Numerous other objects and advanta betterv understood from the following description, which, taken in connection with. the accom anying drawings, discloses a pre ferred em odlment of the devices of the Invention. O Referring to the drawmgs Figure 1 is a side elevatlon showing the working portion of a punch press, mcludmg the dies, and feeding devices embodying my invention;

Figure 2 is a plan view comprising a horizontal cross section taken substantially along line 2-2 of Figure 1;

Fi ure 3 is an enlarged view of a part of the ceding devices of my invention shown in Figure 1;

Figure 4 is a substantially along line 4-4 in Figure 3 Figure 5 is an end view of the feeding mechanism of my invention taken from the left in Figure 3 Figure 6 is a vertical cross section taken subistantially along line 6-6 in Figure 3; an

Figure 7 is a vertical cross section taken substantially along line 7-7 of Figure 3.

To illustrate my invention 1 have shown on the drawings, the operating portion of a punch press 15 including a horizontal work table or bolster plate 13 supported on a pedestal 17 and carrying a die 19, a feeding device 11 and an oiling device 29. The frame of the punch press 15 extends upwardly from the table 13 and carries a vertically reciprocating member 23 slidably mounted in guide ways 25 formed in the frame of the punch press. The reciprocating member 23 carries a punch member 21 at its lower end above the die 19, and is connected with devices (not shown) for imparting a reciprocating movement to the member 23 in such a manner that the punching member 21 periodically engages the die 19 to punch out a portion or otherwise deform or indent a work strip 27 positioned therebetween. The reciprocating mechanism (not shown) may be of any suitable type and includes a shaft rotating at the rate of 1 revolution per operating cycle of the punch carrying member 23. The work strip 27 is arranged in the form of -a roll 39 carried upon a reel 41 adjacent the punch press and is unwound and fed to the punch press through the oiling device 29 which comprises a roller 31 rotatably mounted in support brackets 33 suitably secured to the edge of table 13. The roller 31 is partially immersed in an oil bath carried in a semi-cylindrical container 35 which is supported between the brackets 33. Contact between the strip 27 and the roller 31 is maintained by a holding block 37 secured between the brackets 33.

The reel 41 is rotatably mounted upon a shaft 43 which carriesa tension device 45 having a roller 47 at its free end. This roller engages the strip 27 after it has been unwound from the roll 39 and allows the strip fed intermittently to the punch press without imparting the intermittent movement to the roll 39. Where the intermittent movements of the strip 27 take place rapidly, it is desir able that the roll 39 unwind at a constant rate in order that the inertia of the reel may not horizontal cross section taken Y a belt pulley 55.

'27 to be interfere with the intermittent, feeding movement of the strip 27.

The feeding device 11 engages the strip 27 after it has passed between the punching member 21 and the die 19 0f the punch press which remove a portion of the strip during the punching operation and form apertures 179 successively in the work strip. In the illustrated embodiment, I have shown my device in connection with a punch press adapted to remove circular portions from the work strip, but it will be apparent that my feeding device is equally adapted to operate where portions of any desired configuration are removed, or where the work stri is mere ly indented by the dies or bya suita le marking device, no part of the strip bein removed. The feeding device inclu es a paw-l member 49 adapted to engage the work strip being receivable in the apertures 17 9. The pawl 49 is reciprocated along path of the work strip by suitable mechanisms and is adapted to en age and move the work strip only when trave ling away from the punch press, being formed to ride idly over the strip and leave it stationary when traveling in the reverse direction.

- After leaving the pawl, the work strip passes along a table 87 on which it is supported and is delivered to a take-up reel 51 after passing sharply around the rear edge of the table 87 and a guide roller 181. The reel 51 is similar to the reel 41 and is mounted upon a rotatable shaft. 53 which also carries The take-up reel 51 is rotated, as hereinafter described, through a belt'drive from the main drive shaft of the punch press at a speed suflicient to impart a continuous tension in the end of the work strip in order to wind it tightly on the takeup reel. The guide roller 181 is mounted upon a pin 183 secured in-the edge of the table 13 and is arranged to deflect the work strip around the rear edge 86 of the table 87. This arrangement creates a snubbing action upon the strip and prevents any tension imparted to the strip by the take-up reel from prematurely moving the portions of the stri behind the edge 85, that is to say, in the fee ing device 11, and hence prevents the tension of the take-up reel from effecting the precise operation of the feeding pawl, the snubbing being accomplished by the bending of the strip 27 at 85 and by slippage of the belt drive of the take-up reel.

The mechanism for reciprocating the pawl 49 is mounted upon a supporting frame 57 which has a base 59 arranged for sliding movement along the top of the table 13 in the direction of the path of the work strip 27. A longitudinal ridge 6,1 is formed along the base 59 and is adapted to engage a groove 63 formed in the top of the table 13 to guide the movement of the supporting base 57. The bottom of the slot 63 is enlarged to receive entirely a head 77 adjustment of the the work' strip to clamp shoulders 65 clamping bolts in the slot, the shanks 69 of I 89 extend upwardly from supporting table 87 adjacent the forward end assure the head 67 of clamping bolts and to form for securing the heads of the the bolts extending upwardly through apertures formed in the base 59 and having upper ends threaded for engagement with clamping bolts 61 provided with operating handles 73 by which to secure the supporting frame 57 upon the table 13. Th 57 may be adjusted relative to the table 13 by means of a set screw 75 havin operating handle 77 and rotatab y'mounted in a bracket? 9 which is in turn suitably secured to the end of the table 13. screw has a threaded shank 81 which en ages a threaded aperture formed in the support ing frame 57 and upon rotation of the knurled position .of the supporting frame is accompished. At one side of the supporting frame 57, I provide a bracket, having a portion extendin in a horizontal plane and providing the-strip su porting table 87 over which the stockstrip 27 is adapted to move. Two inte ral ears each side of the thereof. These ears support a shaft 91 which carries a cylindrical roll 93 having a flattened side- 95. and spaced from the table 87 and the stock strip passes across the table beneath the roll. The shaft is normally urged in a counterclockwise direction in Figure 3 by means of a spring 99 57 and to a spring pin 101 secured in the end of the shaft 91 so that the shoulder 97 formed by the intersection of the flattened side-95.

with the. surface of the roll 93 engages the Work'strip and. secures it against the su rting table 87 It is apparent that the work strip 27- may pass beneath the roll 93 in one direction only, that is, toward ure 3 of the d the movement of the work in the rotation of the roll 93 in a counterclockwise direction in Figure 3 and at 001186. quent clamping of the strip between the edge 97 and the shoulder 97 being spring urged toward the table 87 and upon reversal of the direction of it with increasing force between the shoulder and -the which acts as an abutment against which the toggle reacts. I

The pawl 49 is mounted in the forward end of' a reciprocating shaft 103 which is slidably supported in spaced bl 1shings'105 and 106 arranged in the frame 57. is imparted to the shaft 103 by means of a cam 107 mountedon a cam shaft 109 which is arranged parallel to the shaft 103 and which is ijournalle'dadjacent its ends in bushings 111 and 112 suitably supported in the frame 57. he'cam 107 co-operatesjwith a cm.

of the shaft 103. Th e supporting framea knurled This set The roll is supported parallel to -1ng element 130 for secured to the supporting frame,

the left in- Fig rawings and that reversal of. strip will result table 87. The roll 93 in the pres- -ent instance acts as a toggle 'meinber, the

table,

Ajqialmotion d following roller 113 mounted upon a m 114 secured in a cut-out portion115 of the shaft 103. By forming the reciprocatin shaft 103- with the cam follower is arranged ment of the cam and the cam follower I place at a point substantially on the axis e reciprocating force is thus applied axially -to the fllflft 103 so that wear at the bearings 105 an 106, caused by the application of an off center reciprocating force, is eliminated. The cuttin out of the shaft 103 as described reduces the disthe en At the rear of the shaft 103 I form stud 117 of reduced diameter, havin a threaded shank and providing: shou der 119 at the end of theshaft 103 against which a sprin 121is engaged. -.Th1s sprin is threade upon the,stud and is place by means of a sprin housing 123 comprising-a cup shaped mem r having threaded engagement with the rearward end 125 a cut-out portion, in whic 1o seen in v of the bushing 106 the forward edge of the' bushing being provided with a peripheral flange 127 to prevent lateral di lacement of the bushing from its support. e threaded end 'of the stud 117 projects through an aperture in the spririg-housi 128 audiengages an adjusting nut 129 which has a locksecuring it in adjusted position upon the threaded stud-117. The throw of thereciprocating rod 103 may be adjusted by means of the nut 129 wfich limits the forward travel of the shaft by. engagingbehind the end of the springhous- The cam member is rotated once per operating cycle of the punch press and moves the shaft 103 axially away from the dies of the punch press, that is, to the left in Figures Sand 4, against the tension ofthesprlng 121 once during each rotation by the engage ment of the raised rtion of the cam behind the cam follower. y tightening thenut '129 on the stud 117, maybe reduced fro only bvthe throw of zero, the cam follower m a maximum limited the cam member 107 to being raised from cm the throw of the rod 103 gagemenhwith the lower parts ofthe cam member and engaging only the raised gortion of the cam 107 as the throw of the s aft is decreased; The cam'member 107' is arranged to retract the shaft 103 away from the dies during substantially Onequarter of its period of rotation, to allow' the shaft to return under the influence ofithe spring-121 uring substantially another quarter of its period aid to allow'the shaft to remain stationary in fully extended stantially one-half of its period. The punching operation of the die-is arranged occur during the interval while the shaft is stationary.

position for subatin pin is adapted The awl member 49 is formed from a cylindrical rod and is slidably mounted in a diametrical aperture 131 formed vertically throu h the forward end of the shaft 103. A bus 'in 133 is arranged in the aperture 131 to 're ace the wearcaused by the operxial movement of the awl member in t e aperture. The body 0 the pawl is provided with a lon 'tudinal slot 135 adapted to receive the en of a threaded pin 137 arranged through the bushin 133 and the shaft 103 at right angles to t e awl member and having an operating hea 139. This to prevent rotation of the pawl member in the aperture 131. The pawl member may be removed from the aperture 131 for replacement by first removing the in 137 and then withdrawing the pawl memr by means of ahandle 141 provided at its upper end. A pawl tooth 145 is arranged at the lower end of the pawl member 49. The pawl tooth 145 has a bottom surface comprising an inclined plane and providing a raised heel 147 and a depressed toe 149 adapt- "ed to engage the rear-most edge of a rture 179 formed in the strip upon rearwar move ment of the shaft 103 and to move the work strip through a distance equalto the throw of the shaft. During the return travel of the shaft 103, the heel 147 followed by the inclined plane of the pawl, rides over the 155. The sprocket is surface of the work strip and thetoe 149 is received by the succeeding aperture 179 in position to move the strip.

The cam shaft 109 is rotated by a sprocket 151 secured thereon by means of lock nuts driven by a chain 153 which in turn is (not shown mounted on the main drive shaft of the punc press, so that the cam shaft 109 is rotated once during each operating cycle of the punchpress. ries' aworm gear 157 which has driving engagement with a worm wheel 159 mounted on a shaft 161 rotatably mounted in bearings 163 suitably arranged in the supporting frame 57. The shaft 161 carries a belt pulley 165 over which a belt 167 is arranged. The belt 167 engages the pulley 55 on the shaft carrying the take up reel 51 which is thus driven om the main drive shaft of the punch lpress, the parts being arr ged to drive the ta e-up' reel at a speed to exert tension continuously upon the free ends of the punched work strip delivered thereto from the punch press and feeding device slippage of the belt upon the pulley 55 accommodating the increasein diameter of the take-up reel as it becomes loaded with the work strip.

The end thrustof the cam shaft 109 due to operation of the cam member is taken by an end thrust roller bearing 169,. arranged'in a socket 173 formed in the supportin frame 57 adjacent the rearward end of t 'e cam shaft bearing 111, and which engages a shoul driven by a similar sprocket The cam shaft 109 carbearin engagement between a shoulder 17% forme on the camshaft 109 and a peripheral flange 175 formed at the forward end of the rearward cam shaft bearing 112.

It is thou ht that the advantages of the herein deseri d feeding device will be readily apparent. The reciprocating strip engaging andmoving pawl provides a means for drawing an exact through the dies of the press at the completion of each punching cycle, the one way toggle clamp prevents the strip from reversing its movement and from sliding backwardly into the dies while the pawl is moving forward to reengage the strip, the take-up reel winds u the punched strip tightly and neatly .and t e checking clamp exerts a snubbing action which prevents the tension imparted ress.

It will be apparent that numerous changes may be made inthe form and construction of the devices without departing from the spirit and scope of the invention.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is: 1. In a device of the class described, a take up device for receiving a work strip under tension, a member operating on the work strip, and checking means having a member disposed adjacent the path of said strip around prevent said'take up means from effecting movement of the strip past said operating member.

2. In a device of the class described wherein there is a feeding element and a take up device for receiving, under tension, :1. wor strip discharged from said feeding element, and acheckin device comprising a member having a mem er arranged along the path of said discharged strip and around which the strip may be deflected, to prevent the tension imparted to said strip by the take up device from effecting movement of said strip at the feeding device.

3. In a device of the class described, a device for feeding a work strip, a take up device for receiving the work strip under tension, and a snubber for preventing the take up device from advancing the work strip past the feeding device, the snubber comprising a member, and the take up device being in position to draw the work strip around said member to enable said member to exert a snubbing action.

- In witness whereof, I have hereunto subscribed my name.

- CARL G. LILJEBERG.

length of the work strip which the strip may be deflected to 

